A large share of Swiss public contracts is never advertised. Below the thresholds for the open and selective procedures, the authority may decide itself whom to invite in the invitation procedure. For suppliers this means these contracts cannot be found by searching; you have to be known.
How it works
The authority selects suppliers and invites them directly, obtaining at least three bids where possible. Even without publication the principles of procurement law apply: equal treatment of those invited, transparent award criteria, confidentiality of bids. The invited suppliers receive documents that amount to a small specification and submit by a fixed deadline.
Distinction
Unlike the single-tender procedure, in which a contract can go directly to one supplier, the invitation procedure requires competition among several. Unlike the selective procedure, there is no public tender. The value limits are set by the PPA for the Confederation and the IVöB for cantons and municipalities; many municipalities add their own rules.
How to get invited
Authorities invite suppliers they know or that are recommended to them and those that have proven themselves on earlier contracts. Three things demonstrably help: a clear statement of which services you are suited for, ideally with public-sector references; taking part in open procedures of the same authority, even without winning; and visibility where buyers research, from your own website to industry directories.
Legal protection
Whether and to what extent decisions in the invitation procedure can be appealed depends on the applicable law and the contract value. Anyone who cannot follow a rejection should first ask for reasons. For the bid itself the same applies as in large procedures: formal errors and missing evidence cost the contract regardless of the quality of the service.